Carburetor



CARBURETOR. APPLICATION FILED AUG. IB, 19117.

ITU 0 DI. m I, U I` NETE@ STATES WILLIAM GRIKSCHEIT, OF DETROIT,

MICHIGAN.

CARBURETOR.

Laietana.

Application filed August 18, 1917.

To all whom it may concern.'

Be it known that I, WILLIAM GRIKscHnrr, a citizen of the United States, and resident of Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Carburetors, of which the following is a specification.

This invention relates to carburetors for internal combustion engines; and it has for its obj ect to provide a construction whereby an eilicient and reliable explosive mixture of air and hydrocarbon vapor is secured in accordance with the requirements of the engine under varying conditions of speed and load.

One feature of my invention consists in the provision of means whereby an admixture of air and liquid fuel is produced and the mixture efficiently ejected into the path of the primary air and carried thereby into the main mixing chamber of the carburetor.

Another feature of my invention consists in the provision of juxtaposed air and fuel passages communicating with each other and with the mam mixing chamber, means` for supplying air and fuel to said passages, and means for supplying a stream of primary air to the admixture of air and fuel entering the said chamber.

The invention also comprises various `novel` features of construction and combinations of parts which will be hereinafter described and claimed.

In the drawings- Figure 1 is a longitudinal vertical section of a carburetor 'embodying the principle of my invention.

Figs. 2 and 3 are transverse horizontal sections through spaced chambered elements constituting air and fuel passages, as on the lines 2 2 and 3-3 respectively of Fig. 1. Y

Fig. 4 is a bottom view of the basal portion of the central chambered element.

Fig. 5 is a perspective view of the said element detached, a portion thereof being broken away to expose the central spray nozzle.

Fig. 6 is a sectional perspective view of the mixing chamber and its depending wall.

Fig. 7 is a similar View of a tubular casing element having air and fuel inlets at its upper and lower` portions respectively.

Referring to the drawings, 10 designates a float chamber; 11 a fuel inlet thereto, and 12 a gravity valve normally closing the inlet.

Specification of Letters Patent.

)Patented Mar. 28, 1922. Serial No. 186,991.

13 designates a pivotally-mounted float havinga wiper 14 which is adapted to impinge against and raise the valve and thus automatically open the inlet when the fuel within the chamber falls below the normal level. lhe particular form of oat chamber with its adjuncts just referred to is selected for illustration merely; it being here noted that the valve construction indicated forms the subject of a separate application for patent filed by me under Serial N o. 186,990.

15, 16, 17 designate three hollow or chambered elements arranged one within the other in spaced relation to each other and supported centrally within the iioat chamber so as to provide communicating concentric passages or chambers 18 and 19 and a central passage 20 leading to the mixing chamber 20. In the present instance the outer element 15 comprises a vertical tube rigidly supported between the cover 21 and the bot tom of the float chamber; the lower portion of the tube being provided with a iianged foot 22 which is seated in a central opening in the bottom of the float chamber. This tube is preferably internally threaded at its lower and upper portions, as at 23, 24trespectively, for the reception of correspondingly threaded members hereinafter described. The wall of the tube is provided near its basal portion with a series of orifices 25 for the admission of fuel from the fioat chamber to the chamber 18; and it is also provided near its top with a row of orifices 26 for the admission of atmospheric air to the latter chamber. An annular flange 27 formed on the underside of the cover 21 encircles the upper perforated'portion of the tube and forms therewith an air chamber 28 which communicates with the open air by way of a duct 29 in the cover. rThus the air is supplied to and distributed amongst the inlet orifices 26.

The central element 16 comprises a flanged basal portion 30 which is screwed into the threaded lower portion of the tube 15, and also a cylindrical Wall which rises a substantial distance above the base and is contracted at its upper portion to form a constricted central out-let 31. rect air-inlet openingsv 32 are formed in the base 30. Preferably a central upstanding spray nozzle 33 is screwed into the base of the element 16, such base in that case being provided with a diametrical duct 34 which One or more dil affords communication between the bore of the nozzle and the exterior of the element 16.

The intermediate element 17 comprises a dome-like partition which overhangs the venturi and depends slightly below the fuel inlet orifices 25 of the tube. The dome 1T is lpreferably an integral part of a depending neck 35 formed on a cylindrical body 36 which extends through the cover of the float chamber, said body being provided with a suitable screw-threaded portion 3S which is engaged with the upper threads of the tube 15. The interior of the body 36 constitutes a mixing chamber, the same comprising a passage, preferably tapering or flaring outwardly, extending longitudinally through the body 36 and neck The inner or narrow end of the mixing chamber corresponds substantially in area with and lies in close relation to the outlet 31 of the element 16; the upper end of the chamber being connected with the manifold of the engine as usual.

By virtue of the curvature of the adjacent upper walls of the elements 16, 17 the upper portion of the chamber 19 is gradually reduced and a thin annular outlet 40 therefrom to the mixing chamber 20 is provided, and by virtue of the neck-like formation of the wall at the foot of the latter chamber a relatively large annular air space 41 merging with the upper portion of the chamber 18 is provided, as clearly seen in Fig. 1.

In the operation of the described carburetor initially both chambers 18 and 19 will be filled with liquid fuel (to the level of the fuel in the float chamber), forming a liquid seal preventing access of air to the mixing chamber from the air chamber 28. The flow of air through the passage 2O will exercise an asperating action at the nozzle 33, and

also at the annular outlet 40, causing a flow of fuel from said nozzle and outlet. lf the flow from said nozzle and outlet is more rapid than the discharge of fuel from the float chamber through the ports 25. the level of fuel in the chamber'18 will fall so as to finally break the liquid seal and permit air fiowing through the space 41 from the chamber 28 to co-mingle with the li uid fuel discharging from the orifice 40. (fhving to the discharge of liquid fuel, or of a mixture ofA air and fuel from the opening 10 inthe form of a thin annular jet angular-ly impinging upon the stream of fuel laden air arising through the opening 31 a very efficient carbureting action results.

The above described construction and arrangement of the several chambers and passages, including the central spray nozzle, ensures the Substantial equalization of the pressure between the main or float chamber and the passages, or, in other words. the pressure in the concentric chambers may be almost the same as in the float chamber when the engine is started; thus ensuring a substantially uniform condition of the explosive mixture delivered to the engine under varying loads and speeds.

The central spray nozzle may be omitted if desired, in which case the primary mixture of air and oil will be ejected through the annular outlet only during the operation of the engine.

While I have herein shown and described a preferred form of embodiment of my invention, it is to be understood that l do not limit myself to the particular details of construction disclosed as the same may be widely varied without departing from the spirit ofmy invention as defined in the appended claims.

I claim- 1. A carburetor having a main mixing chamber, and three passages arranged in spaced relation to each other adjacent to the inlet ofsaid chamber, the central passage communicating with the inlet of and providing means for directing air to said chamber, the intermediate passage having a restricted annular portion opening into said inlet` the lower portions of the outer and intermediate passages being in open communication with each other, and the outer passage having a fuel inlet adjacent to its lower portion and an air inlet above said fuel inlet.

2. A carburetor having a main mixing chamber, three passages arranged in spaced relation to each other adjacent to the inlet of said chamber, and a fuel spray 'nozzle within the central passage, said central passage communicating with the inlet of and providing means for directing air to said chamber, the intermediate passage having a restricted annular portion opening into said inlet, the lower portions of the outer and intermediate passages being in open communication with each other, and the outer passage having a fuel inlet communicating with the basal portions of the inner chamber and the spray nozzle and also having an air inlet about the fuel inlet.

3. A carburetor having a main mixing chamber, means for supplying a current of air to said chamber longitudinally thereof, concentric passages surrounding the path of the current of air to said mixing chamber, said passages being in communication with each other at theirlower portions, the inner passage having at its upper portion a restricted annular outlet surrounding the path of the air to the'mixing chamber, the outer passage having an air inlet at its upper portion and a fuel inlet at its lower portion.

4. A. carburetor having a main mixing chamber, means for supplying a current of air to said chamber longitudinally thereof. concentric passages surrounding the path of the current of air to said mixing chamber, said passages being in communication with each other at their lower portions, the inner passage having at its upper portion a restricted annular outlet surrounding the path of the air to the mixing chamber, the outer passage having an air inlet at its upper portion and a fuel inlet at its lower portion, and a spray nozzle axially below the mixing chamber and Within the path of the air current, said nozzle -being in Acommunication with the basal portions of the concentric passages.

5. A carburetor having a float chamber, a main mixing chamber, a tubular air intake element arranged within the float chamber and communicating with the mixing chamber, a dome overhangng the body of said air intake element, and a tube surrounding the dome, said air intake element dome and tube being in spaced relation to each other to provide two concentric passages exteriorly of said air intake element, said passages being in communication their lower portions, the inner passage havwith each other at' ing at its upper portion a restricted annular Signed at Detroit in the county of Wayne l and State of Michigan, this August A. D. 1917.

WILLIAM GRIKSCHEIT.

16th day of 

